Question

Jawab plisss ini sambungan dari yang tadi

Answer 1

31. 2a + b = 2(3) + (-4) = 6 - 4 = 2

35. 4a + 2b
4(-4) + 2b
-16 + 2b
2b = 16
b = 16 : 2 = 8

36. 2x + y = -5 Ι x5
5x + 3y = -12 Ι x2
--------------------------
10x + 5y = -25
10x + 6y = -24
---------------------(-)
-y = -1
y = 1


37. 2x + 2y = 12 Ι x3
3x + 5y = 22 Ι x2
----------------------------
6x + 6y = 36
6x + 10y = 44
-------------------(-)
-4y = -8
y = -8 : -4 = 2

2x + 2y = 12
2x + 2(2) = 12
2x = 12 - 4
x = 8 : 2 = 4

Jadi, x - y = 4 - 2 = 2

38. 3x - y = -9 Ι x1
x + y = 1 Ι x3
-------------------------
3x - y = -9
3x + 3y = 3
-----------------(-)
-4y = -12
y = -12 : -4 = 3

3x - y = -9
3x - 3 = -9
3x = -9 + 3
x = -6 : 3 = -2

Jadi, 4x + 2y = 4(-2) + 2(3) = -8 + 6 = -2